Originally Posted by Tom K.
You might try to research how registration affects not just the battery but also the IBS and other electrical components. My understanding is that if the battery is not registered, it may result in an under OR overcharging condition. When the IBS on my E91 developed an intermitent fault, it was sending out 17.5 volts, & I was told that could adversely affect some electric components. As it was, the car would stall, show error messages and ultimately a new battery ( as well as alternator & IBS) was required.
I agree with you. We all want to save money, but imho there are times to just part with it. It would be like getting 4 new tires, and not paying the $59.99 (not a BMW) for the alignment. Yeah, you saved $60, but there'll be extra wear on the tires which will have a shorter life.